Is Digoxin a Good Choice for Treatment of Atrial Fibrillation?

Is Digoxin a Good Choice for Treatment of Atrial Fibrillation? I want to make it clear, once again, that I am writing this blog as an endurance athlete dealing with atrial fibrillation (AF) – not as a clinician. I’m not a cardiologist or a primary care physician. I’m simply posing a question and not answering it. It is important for you to be in agreement with your cardiologist and primary care provider about your treatment plan Whatever you do – DON’T STOP TAKING ANY MEDICATION YOU HAVE BEEN PRESCRIBED BECAUSE YOU READ ABOUT SIDE EFFECTS ON SOME GUY’S BLOG!

Also – full disclosure – I take a low dose of digoxin.

Digoxin is the generic name for Lanoxin which has been actually been used for hundreds of years as an herbal preparation (Digitalis) from the foxglove plant, seen above, which is a lovely plant, don’t you think?

Digoxin is used to treat atrial fibrillation, atrial flutter, and heart failure. My cardiologist told me that many of the younger cardiologists don’t generally even prescribe it any longer.

Digoxin has a narrow therapeutic index, which means that at too low of a dose it isn’t very effective and at higher doses it is toxic. Because of this it has many side effects. It is unknown whether digoxin is safe during pregnancy. Digoxin works by improving heart function by strengthening the contractions and slowing the heart rate.

A 2018 paper published Journal of the American College of Cardiology concluded that digoxin increased mortality in patients with atrial fibrillation regardless of heart failure.

Conclusions In patients with AF taking digoxin, the risk of death was independently related to serum digoxin concentration and was highest in patients with concentrations ≥1.2 ng/ml. Initiating digoxin was independently associated with higher mortality in patients with AF, regardless of heart failure.

Yikes!

Also consider that several of the authors of the study disclosed that they had financial ties to pharma and medical device companies, including pharmaceutical giants Bristol-Meyers Squibb and Pfizer who funded the study.

But look! Runners and other endurance athletes need to ask their cardiologists about digoxin toxicity because both dehydration and low magnesium increase the chance of toxicity. Who among us hasn’t been dehydrated?

I’m going to be asking my cardiologist more questions about digoxin next time I see her. As I mentioned I take a small dose and when we did lab work my digoxin level was low, below the therapeutic window, which she said was fine – she just wanted to make sire it wasn’t too high. Me too!

I’d love to see your comments!

Dehydrated Trail Runner – me!

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Coffee and Atrial Fibrillation – Update

A couple of years ago I posted an article on this block entitled Does Drinking Coffee Cause Atrial Fibrillation?   

It had been determined that drinking coffee, even in fairly large amounts, did not increase the risk of an individual going into atrial fibrillation.

 

In their analysis, the researchers found that coffee consumption was not associated with AF incidence, even in more extreme levels of coffee consumption.

 

The article went on to state that while drinking coffee does not cause atrial fibrillation individuals who have no history of atrial fibrillation, it was thought that coffee may be related to recurrence of atrial fibrillation and individuals who have the arrhythmia intermittently:

 

“These findings indicate that coffee consumption does not cause atrial fibrillation,” Larsson says. “However, high coffee consumption may still trigger arrhythmia in patients who already have atrial fibrillation.”

 

 

It was stated that more research was necessary. 

A recent, widely reported Australian study, a very large review of existing studies, determined that coffee is likely safe for people with atrial fibrillation.

 

“Although coffee increases your heart rate, it does not make it abnormal,” explained senior researcher Dr. Peter Kistler.  . . . “We found that there is no detrimental effects of coffee on heart rhythm and, in fact, coffee at up to three cups per day may be protective,” he said.

 

Protective?  That sounds like terrific news!  It is always nice to find out that something that is so enjoyable, but which you have assumed is possibly unhealthy, turns out to be not only safe but good for you also, reducing, to a small extent, episodes of atrial  fibrillation.

 

 Kistler’s group found that, among more than 228,000 patients, drinking coffee cut the frequency of episodes of atrial fibrillation by 6 percent. A further analysis of nearly 116,000 patients found a 13 percent risk reduction.

One cup of coffee contains about 95 milligrams of caffeine and acts as a stimulant to the central nervous system.

Caffeine also blocks adenosine, a chemical that can trigger atrial fibrillation, Kistler explained.

 

This study did, however, go on to recommend that people with heart arrhythmias avoid caffeinated energy drinks.  Furthermore, people who are sensitive to caffeine, should still avoid coffee.  Again there are certain people who identify caffeine is a trigger for atrial fibrillation and those individual should, by no means, return to drinking coffee.

 

Please comment with respect to your experiences with coffee, energy drinks, and atrial fibrillation.  Thanks!

The original study can be found here:

 Peter Kistler, MBBS, Ph.D., director, electrophysiology, Alfred Hospital and Baker Heart and Diabetes Institute, Melbourne, Australia; Byron Lee, M.D., professor, medicine, director, electrophysiology laboratories and clinics, University of California, San Francisco; April 16, 2018, JACC: Clinical Electrophysiology

Whatever Happened to AFIB Ultrarunner?

Sunrise at the start of an ultramarathon

So, whatever happened to “that one guy?” The one with the AFIB Ultrarunner blog?

When I decided to start this blog I had, of course, scanned the internet for similar blogs, and I found AFIB Ultrarunner. This was a somewhat short-lived but excellent 2010 blog by an unnamed man who was an ultrarunner, who like me, was dealing with atrial fibrillation (AF).

Afibultrarunner” was actually the name I originally chose for this blog, but it was taken so that’s okay, I’d be simply “afibrunner.”

I’m particularly interested in contacting him for two reasons.

First of all, at the time I was starting this blog I was personally just starting to train for ultras. In fact, I went into permanent AF right at the end of a twenty mile training run while trying to train for my first 50K.  I didn’t really know how to train so I was simply running a twenty mile trail run every weekend and I truly loved those long, slow training runs; but evidently that wasn’t a good idea given what happened!

Second of all the AFIB Ultrarunner guy had had an ablation, and has an excellent description of his experience. I have never had an ablation and likely never will (I’ve been told my chances at success are poor) and wanted to find out how he did on a long term basis. At this point I’d really like to find somebody to write about the experience for this blog – but I’ve never been able to find out who he is or how to contact him.

His blog is excellent and ends, I think, on a very sad note:

My cardiac procedure was painful or uncomfortable in constantly new ways for 20 hours.  I think I took it

pretty well, but at the time I thought that that day would be amongst the worst in my life, as in up

there with losing a spouse, child or dying yourself (although this just might be my inexperience with death speaking.)  Also I tried two drugs and nothing worked. Also my condition effects my day to day life more, such as it is now harder to carry dog food from the car without an attack, and my running has suffered.

Lets hope 2011 has more adventure running, and less heart problems.

 

And that was the end. I’m curious. How’s he doing now? Still running? Still dealing with AF? Maybe he doesn’t want to talk about it anymore – he is a little secretive about his identity, although there is a photo of him during a 50 mile race but there’s no contact info. A fifty mile race while dealing with AF – not too shabby!

Hey, man, if you’re out there let me know!

Alcohol, Athletes, and Atrial Fibrillation

Alcohol, Athletes, and Atrial Fibrillation

 

Beer drinking with my buddies at Marster Springs Campground

Does alcohol cause atrial fibrillation (AF)?

We’ve been reading for years that a glass of wine or two can reduce the risk of heart attack and stroke; and it’s pretty clear if you’ve been hanging around at the finish lines of marathons, ultras, and long distance bicycling events that endurance athletes like to drink alcohol. Also, some studies have shown that endurance athletes have up to a five-fold increase risk of AF

So . . . is alcohol consumption a risk factor for endurance athletes dealing with AF?

Uhh . . . yeah.

Drinking alcohol frequently raises the likelihood of developing AF,  and more alcohol means more risk. One to three drinks (considered to be “moderate drinking”) increases the chances of AF, and “heavy drinking” (four or more drinks per day) increases the odds even more. It’s been suggested that every extra daily drink increases the risk by 8%!

Even if you aren’t a daily drinker so-called binge drinking, defined as five or more drinks in a day, also increases the chances of AF. (Some call it “binge drinking,” I might call it any weekend during my college years!)

Typical weekend from my college days

So how much alcohol is safe? Once you’ve been diagnosed with AF one or two drinks per day is probably safe, but three or more may be likely to trigger an episode. Also – make sure you figure out how much alcohol is one drink – a standard glass of wine versus a large glass of wine. A bottle of American light beer is going to be less alcohol than a bottle of craft brew IPA or stout.

My personal advice is that once you are diagnosed with AF the best move would be to quit alcohol altogether. That’s what I did. But consider that this advice is coming from a guy who is in permanent AF.

A very helpful WebMD article advises that even with moderate drinking you should avoid drinking every day: 

Even if you drink moderately, experts suggest you take a few days off from drinking alcohol every week.

  • Limit yourself to one to two drinks a day.
  • Try to have 2 to 3 alcohol-free days every week.
  • Talk to your doctor if you have an episode of AFib within an hour of drinking alcohol.

 

Exactly how does alcohol increase the chances of AF?

It isn’t clear why, but it is thought that hit might be related to increasing vagal tone. The more alcohol you drink, the higher the vagal tone. Another idea is that dehydration caused by alcohol triggers AF. A lot of people with AF know that alcohol can trigger their AF. Let’s face it – alcohol is basically a toxin with some pleasant side effects.

If you already are being treated for AF alcohol can interfere with the treatment – increase blood pressure, interact with anticoagulants, etc.

What is “Holiday Heart”?

Basically it is a nickname for the way heavy drinking around the holidays, so called “binge drinking” can trigger AF. According to Medscape:

Holiday heart syndrome most commonly refers to the association between alcohol use and rhythm disturbances, particularly supraventricular tachyarrhythmias in apparently healthy people. Similar reports have indicated that recreational use of marijuana may have corresponding effects.

 

The most common rhythm disorder is atrial fibrillation, which usually converts to normal sinus rhythm within 24 hours. Holiday heart syndrome should be particularly considered as a diagnosis in patients without structural heart disease and with new-onset atrial fibrillation.  Although the syndrome can recur, its clinical course is benign, and specific antiarrhythmic therapy is usually not indicated. Interestingly, even modest alcohol intake can be identified as a trigger in some patients with paroxysmal atrial fibrillation. 

Finally – what is meant by “Drinker’s Heart” (a.k.a “beer drinker’s heart”)?

That’s cardiomyopathy, a serious disease of the heart muscle, related to chronic heavy drinking. Don’t let it happen to you. It’s bad.

 

beerMPG

I would love to have any readers with comments post them below. I’d love to hear from  athlete’s with atrial fibrillation who have had experience with alcohol as a trigger. Thanks for reading.

 

Endurance Sports and Atrial Fibrillation – WHY?

Endurance Sports and Atrial Fibrillation – WHY?

starting a long run on the local PCT. We saw a bear that day – fun.

Exercise is supposed to be good for you, good for your heart, right? Then why is that endurance athletes have two to ten times the rate of developing atrial fibrillation compared to “normal” people? Is a little or moderate exercise good but excessive exercise bad? As an endurance athlete (marathons, trail running, long distance mountain and road biking) who has permanent atrial fibrillation (AF) I would certainly like to understand “WHY?”

There is a terrific article on Europace entitled Endurance Sport Practice as a Risk Factor for Atrial Fibrillation and Atrial Flutter . By internet standards it’s a long read but I will review it here.

The studies aren’t large, and male athletes predominate – but it is clear that endurance athletes have, as mentioned above – 2 to 10 times the likelihood of developing AF. It is not actually known why but it is thought that ectopic atrial beats, chronic inflammation, and larger atrial size are all risk factors.

Personally – the story checks out – I started having runs of “premature atrial contractions” years before ever going into AF, and because endurance athletes train more frequently and tend to avoid rest the atria are chronically inflamed, which leads to fibrosis (scarring) of the atrial muscle. And of course my left atrium has been severely enlarged for decades – not as much because of sports but because I had previously had mitral regurgitation (repaired surgically 1994 but the atrium never shrunk back to normal).

But even without the mitral valve issues endurance athletes tend to have enlarged atria. And we don’t rest enough leading to inflammation and scarring. The Europace article cites several studies that link long term endurance sports with AF, compared to sedentary individuals.

Moderate exercise may actually protect against AF.

Ringo after a long run – Fremont Trail

The Europace article also cites studies that show a correlation with “occupational physical activity” and AF – meaning people that have difficult, physically demanding jobs are also in the same boat as endurance athletes.

I didn’t know this – there is also a higher rate of AF related to how tall a person is – damn! I’m 6’3” (or 6’4” – depending on what year was measured.)

The article discusses, speculates, as to the mechanism of AF in the athlete’s heart but much of this is a bit technical for this blog. Feel free to explore the article if you are curious.

The typical clinical profile of sport-related AF or atrial flutter is a middle-aged man (in his forties or fifties) who has been involved in regular endurance sport practice since his youth (soccer, cycling, jogging, and swimming), and is still active. This physical activity is his favourite leisure time activity and he is psychologically very dependent on it. 

Interestingly the AF rarely occurs during running:

They almost never occur during exercise. This makes the patient reluctant to accept a relationship between the arrhythmia and sport practice, particularly since his physical condition is usually very good. The crises typically become more frequent and prolonged over the years and AF becomes persistent. Progression to permanent AF has been described by Hoogsteen et al .

Again, for me, the story checks out. I certainly recall long episodes of palpitations at rest that I now can identify as AF – until the day when it became (dreaded) permanent AF!

The article suggests that abstinence from sports is helpful for athletes having episodes of AF, although it isn’t curative. The problem, as any endureance athletes knows, is that it is nearly impossible to get us to give up our long runs, bike rides, etc.

Other therapeutic measures are also discussed – but that is a talk that is best left to the runner and the cardiologist.

Although ablation seems to be quite effective, endurance sport cessation associated with drug therapy seems to us a more suitable approach as an initial therapy, particularly in non-professional, veteran athletes.

To conclude I’m just going to quote their conclusions right here:

Vigorous physical activity, whether related to long-term endurance sport practice or to occupational activities, seems to increase the risk for recurrent AF. The underlying mechanisms remain to be elucidated, although structural atrial changes (dilatation and fibrosis) are probably present. There is a relationship between accumulated hours of practice and AF risk. Further studies are needed to clarify whether a threshold limit for the intensity and duration of physical activity may prevent AF, without limiting the cardiovascular benefits of exercise.

I’d be interested in others opinions and experiences with these issues. Reading this article was a little emotional for me – like I said – the story checks out! I guess that if I knew what I know now I might have cut down a little on the endurance sports before I was forced to do so by permanent AF. Truly, for me, a day long run with my dog, on a trail, in a local wilderness area was the most enjoyable thing I can imagine. And at this point it isn’t even the AF preventing me from still doing it – it’s the  high dose of beta blocker I take for rate control – really takes the wind out of my sails.

 

 

“C’mon Boss, let’s go for a trail run!”

Bariatric Surgery Lowers the Risk of Atrial Fibrillation

Bariatric Surgery Lowers the Risk of Atrial Fibrillation

I’m not sure how much this applies to endurance athletes, but I found this interesting. As, I think, everyday knows, obesity increases the risk of cardiovascular disease, and that includes atrial fibrillation. Researchers in Sweden recently published a study where they followed 4200 obese individuals with normal sinus rhythm (ie. not in a fib at the beginning of the study) for an average of nineteen years. During that period approximately half of the subjects had had bariatric surgery – basically various surgical procedures to rearrange the internal organs to force the patient to eat less and absorb less resulting in significant, life-changing weight loss.

The study found that 12.4% in the surgery/weight loss group experienced atrial fibrillation compared to 16.8% in the non-surgical/still obese group. That’s a 29% lower rate of developing atrial fibrillation for the surgery/weight loss group. Furthermore the study also concluded that, “Compared with usual care, weight loss through bariatric surgery reduced the risk of atrial fibrillation among persons being treated for severe obesity. The risk reduction was more apparent in younger people and in those with higher blood pressure.”

(Citation is HERE)

Other studies have shown that weight loss can be helpful in reversing atrial fibrillation and that ablation success rate is improved with weight control. I don’t have literature citations but I read this here.

So what does this have to do with endurance athletes with A fib? All endurance athletes are already thin, right? Well, obviously that isn’t true; but probably very few endurance athletes would meet the criteria for bariatric surgery. So we should be in the low risk group to begin with – so why do so many endurance athletes end up in a fib?

Well, as everybody knows distant runners and other endurance athletes often gain weight when they have to quit or reduce exercises because of, say, atrial fibrillation. These studies suggest better outcomes with weight control regardless of method.

As to why endurance athletes have a higher rate of A fib – I’ll address that in next weeks post.

Thanks for reading – please feel free to post comments below.

Afib Runner News Update – Vitamin D Helps with Heart Failure & Exercise Helps Atrial Fibrillation Outcomes

brownmountaintrailBrown Mountain Trail

Vitamin D Helps with Heart Failure

I’m not certain this first item has much to do with readers of this blog – theoretically we are getting outside and getting plenty of sunshine, but a recent study showed that supplementation with high doses of vitamin D improved left ventricular structure and function in patients with chronic heart failure, although it doesn’t improve walking distance (citation below). I think the people in this study were a little worse off than a typical afib runner. In this study the non-placebo group received 4000 IU of vitamin D.

Personally, I like to supplement with vitamin D – one of two supplements that I take. I tested my vitamin D levels via a blood test several years ago and was at the low end of normal even with modest supplementation. This is interesting considering that I was running about 35 miles a week, all outdoors!

The other supplement I take is B complex – pretty standard for vegetarians.

Good news for fib runners: Exercise is good for your a trial fibrillation!

At the recent American College of Cardiology’s 65th Annual Scientific Session & Expo, findings were presented that show exercise reduces risk of cardiovascular death and all cause death. And it appears that the more you exercise the better the outcome.

I have a citation below, but I will summarize by saying that in a European study with over 2000 patients, subjects were divided into four groups based on weekly exercise: none (38.9%), occasional (34.7%), regular (21.7%), and intense (4.7%). In a two year follow up it was determined the “regular” and “intense” group had lower death rate, improved outcomes, etc. And of course the “intense” group did better than the “regular”, “regular” did better than “Occasional,” etc.

So there you go – justification for continuing to work out with atrial fibrillation. It seems obvious but it is nice to see proof.

Vitamin D and hearth failure:

Witte KK, Byrom R, Gierula J, et al. Effects of vitamin D on cardiac function in patients with chronic HF: the VINDICATE study [published online April 2016]. J Am Coll Cardiol. doi:10.1016/j.jacc.2016.03.508.

Exercise and afib:

Proietti M, Boriani G, Laroche C, et al. Physical activity and major adverse events in patients with atrial fibrillation: A report from the EURObservational research programme pilot survey on atrial fibrillation (EORP-AF) general registry. Paper presented at: 65th Annual Scientific Session & Expo; April 4, 2016; Chicago, IL. http://www.abstractsonline.com/pp8/#!/3874/presentation/42867.